The present invention relates to color splitting filters for a television camera, and more particularly to such filters that provide three output light colors that are complementary to the prior art red, blue, and green primary colors respectively.
The standard prior art color camera uses a beam splitter, such as dichroic mirrors or a prism, to respectively provide R (red), B (blue), and G (green) color output light beams to three imagers, such as vidicons or CCD (charge coupled device) imagers. For best colorimetry, the ideal R, G, and B filters require negative lobes at certain wavelengths, which lobes are not physically realizable. As a result, practical cameras use taking characteristics (spectral responses) that are designed so that negative lobes are not required. The design process for the filters is an optimization process to minimize color errors. Further reduction of color errors is possible by matrixing; however this lowers the signal-to-noise ratio, which lowering is proportionally greater for the B channel due to the low luminosity of blue and to the generally low sensitivity of the B sensor.
It is therefore desirable to have a camera that has both improved colorimetry and improved signal-to-noise ratio.